Transgene silencing in plants, RNA interference in animals and quelling in fungi are related processes representing a recently discovered cellular system for suppression of transposons and viruses. Through mutation analysis several components of the mechanism have been identified and, in Drosophila, an in vitro system is leading to biochemical characterization of RNA interference. Research into these phenomena is currently at an exciting stage involving diverse model systems and approaches. The "RNA interference, cosuppression and related phenomena" program is designed to compare and contrast the findings from the various systems as a means of drawing out full understanding of the underlying mechanisms. The meeting will also cover enabling technologies based on RNA interference and cosuppression. Research programmes based on RNA interference and related phenomena are likely to lead to novel strategies for protection against virus disease and other new approaches to health related therapy in animals. It is also likely that there will be improvements in disease resistance and nutritional quality of crop plants. These developments will follow directly from understanding the role of RNA interference and related phenomena as a protection mechanism and from the application of novel enabling technologies. The joint organization of "RNA interference, cosuppression and related phenomena" with the meeting on "Epigenetics in Development and Disease" meetings will allow exploration of related issues in the topics of the two meetings.